SCPS314 December   2025 TCA9536-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 I2C Bus Timing Requirements
    8. 5.8 Switching Characteristics
    9. 5.9 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 I/O Port
      2. 7.3.2 P3 or Interrupt (INT) Output
      3. 7.3.3 Pull-up Disable Functionality
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power-On Reset
      2. 7.4.2 Powered-Up
    5. 7.5 Programming
      1. 7.5.1 I2C Interface
        1. 7.5.1.1 Writes
        2. 7.5.1.2 Reads
      2. 7.5.2 Software Reset Call
    6. 7.6 Register Maps
      1. 7.6.1 Device Address
      2. 7.6.2 Control Register and Command Byte
      3. 7.6.3 Register Descriptions
  9. 8 Application Information
    1. 8.1 Typical Application
      1. 8.1.1 Design Requirements
        1. 8.1.1.1 Minimizing ICC When I/Os Control LEDs
      2. 8.1.2 Detailed Design Procedure
      3. 8.1.3 Application Curves
  10. 9 Power Supply Recommendations
    1. 9.1 Power-On Reset
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

8.1.1.1 Minimizing ICC When I/Os Control LEDs

When the I/Os are used to control LEDs, they are normally connected to VCC through a resistor as shown in Section 8.1. The LED acts as a diode so, when the LED is off, the I/O VIN is about 1.2V less than VCC. The supply current, ICC, increases as VIN becomes lower than VCC.

Designs needing to minimize current consumption, such as battery power applications, should consider maintaining the I/O pins greater than or equal to VCC when the LED is off. Figure 8-2 shows a high-value resistor in parallel with the LED. Figure 8-3 shows VCC less than the LED supply voltage by at least 1.2V. Both of these methods maintain the I/O VIN at or above VCC and prevent additional supply-current consumption when the LED is off.

TCA9536-Q1 High-Value Resistor in Parallel with the LEDFigure 8-2 High-Value Resistor in Parallel with the LED
TCA9536-Q1 Device Supplied by a Lower VoltageFigure 8-3 Device Supplied by a Lower Voltage